Posted: 1/15/2016 6:46:59 PM EDT
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I recently had my home's electrical service upgraded to 200A and a new Eaton 40 slot panel installed. The electrical inspector came today and the upgrade did not pass inspection for 2 reasons.
1. There is no intersystem bonding bridge for the utility companies to tie into. AT&T currently has a cable clamp on the #4 bare copper wire that runs from the circuit breaker panel to the ground rods outside. The inspector told me I could mount the bridge inside or outside and clamp a #4 wire to the existing wire and run that to the bridge. That's something I can do in an hour, and quite honestly just never noticed it wasn't there. I'll have to look, but I don't think any of the existing cable has enough slack to pull into a bridge if I mount one. 2. My home has interruptible A/C service which is fed by a second meter outside. #6 XHHW-2 runs from this second meter to a separate circuit breaker panel with a 2-pole 30A breaker and a single bus bar with the neutrals connected to it right now. The inspector told me to run a #10 from the panel and connect it to the #4 copper coming from the other panel out to the grounding rods. This is where I'm confused. How should this be grounded? It's not a subpanel because it's fed by the mains, and not by the other panel. Do I need to install a second bus bar for the grounds, or can the ground be connected to the single bus bar in there? 2a. I'm also wondering about my A/C compressor now. There is a fuse box outside next to the compressor with a ground running to the A/C compressor, but that appears to be connected to the same busbar as the neutral? Now for the pictures: Electric meters outside: Link 
A/C service panel in the basement: Link 
Main service panel in the basement: Link 
Main service panel close-up: Link 
A/C fuse box outside next to compressor: Link 
ETA: The Dropbox pictures aren't loading here, but the links are good. |
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Your A/C doesn't have a neutral.
I can't believe your inspector didn't nail you for the connector going into the side of the meter, it doesn't look to be weather tight. ETA- After looking at the photos again I noticed some other items that are not correct, items your inspector should have caught. You have SEU (2 hots and a ground) feeding your panel, should have ran SER (2 hots, neutral and ground) instead. Doesn't look like you used any nolox on any of the Al wire. Nolox keeps the Al from oxidizing and loosening up the connection, which causes the wires to heat up, which causes fires. |
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If the AC has a separate meter then I think it's considered a second service and requires it's own grounding connection to the ground rods. It is a 240 volt only service so there is no neutral or neutral buss.
Everything in the A/C service disconnect looks okay, except of course the apparently exposed wire feeding it. I don't know anything about an intersystem bonding bridge. Maybe it's new or maybe it's a Michigan thing. Any wire coming out of those meter bases should be in conduit. Anything line voltage that is subject to the elements and potential damage should be in conduit. Disclaimer: I'm an electrician, but not that kind of electrician. |
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Some states allow the use of "SE" cable to run exposed on the outside of the house. It is rated for it (UL) and allowed. (not in my state though) The local AHJ and utility will determine that. Like others have said the A/C has no neutral but, if it is on it own service then there should be a neutral to it (from the service side) and landed on the ground bar with the circuit ground. It wont be used but that's the way it has to be done here (Wa state). The inter-system bonding is a lug kit like this one http://www.aifittings.com/catalog/grounding/intersystem-grounding-bridges-with-pvc-adapter/GBB5P You'll need to size the bond wires to the each of your service's. |
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Quoted:
Your A/C doesn't have a neutral. I can't believe your inspector didn't nail you for the connector going into the side of the meter, it doesn't look to be weather tight. It's a Halex 10401 cable clamp, which I do not believe is weather tight. This box was installed by 2 licensed electricians, inspected by the utility company prior to upgrading the meter, and inspected by the city inspector. No one has said anything about that clamp. ETA- After looking at the photos again I noticed some other items that are not correct, items your inspector should have caught. You have SEU (2 hots and a ground) feeding your panel, should have ran SER (2 hots, neutral and ground) instead. I do believe it's SEU, but it's being used as 2 hots with a concentric neutral. There is no ground except for the #6 bare copper from the main panel to the ground rods and water pipes. The utility company's feed has 2 hots, and a support wire that the concentric neutral from my weather head is clamped to. Picture of utility company feed Doesn't look like you used any nolox on any of the Al wire. Nolox keeps the Al from oxidizing and loosening up the connection, which causes the wires to heat up, which causes fires. I didn't do the install, but there is paste on the main panel lugs holding aluminum wires from what I can tell. I'll have to double check the A/C panel. Quoted:
Your A/C doesn't have a neutral. I can't believe your inspector didn't nail you for the connector going into the side of the meter, it doesn't look to be weather tight. It's a Halex 10401 cable clamp, which I do not believe is weather tight. This box was installed by 2 licensed electricians, inspected by the utility company prior to upgrading the meter, and inspected by the city inspector. No one has said anything about that clamp. ETA- After looking at the photos again I noticed some other items that are not correct, items your inspector should have caught. You have SEU (2 hots and a ground) feeding your panel, should have ran SER (2 hots, neutral and ground) instead. I do believe it's SEU, but it's being used as 2 hots with a concentric neutral. There is no ground except for the #6 bare copper from the main panel to the ground rods and water pipes. The utility company's feed has 2 hots, and a support wire that the concentric neutral from my weather head is clamped to. Picture of utility company feed Doesn't look like you used any nolox on any of the Al wire. Nolox keeps the Al from oxidizing and loosening up the connection, which causes the wires to heat up, which causes fires. I didn't do the install, but there is paste on the main panel lugs holding aluminum wires from what I can tell. I'll have to double check the A/C panel. Quoted:
If the AC has a separate meter then I think it's considered a second service and requires it's own grounding connection to the ground rods. It is a 240 volt only service so there is no neutral or neutral buss. So the concentric neutral on the feeder from the meter is not actually neutral? Everything in the A/C service disconnect looks okay, except of course the apparently exposed wire feeding it. I don't know anything about an intersystem bonding bridge. Maybe it's new or maybe it's a Michigan thing. It was added to the NEC in the 2008 revision I believe. NEC 250.94 Bonding for Other Systems provides the requirements. Intersystem bonding bridges are cheap and easy to install. Any wire coming out of those meter bases should be in conduit. Anything line voltage that is subject to the elements and potential damage should be in conduit. Disclaimer: I'm an electrician, but not that kind of electrician. Quoted:
Some states allow the use of "SE" cable to run exposed on the outside of the house. It is rated for it (UL) and allowed. (not in my state though) The local AHJ and utility will determine that. This must be the case here. The utility company technician inspected the install prior to upgrading the meter and had no issues. The city electrical inspector has inspected it and also had no issues. Like others have said the A/C has no neutral but, if it is on it own service then there should be a neutral to it (from the service side) and landed on the ground bar with the circuit ground. It wont be used but that's the way it has to be done here (Wa state). So if I understand this, the A/C circuit breaker panel is treated like a main service panel, and not a subpanel. Therefore, the single bus bar is a shared ground/neutral bus? Therefore, the feed from the meter contains a concentric neutral, but the feed from the panel to the A/C uses the concentric wire as the ground since the A/C compressor does not need a neutral? So, to make this correct, I need to connect a ground cable from the bus bar in the A/C panel to the ground cable going to the ground rods? The inter-system bonding is a lug kit like this one http://www.aifittings.com/catalog/grounding/intersystem-grounding-bridges-with-pvc-adapter/GBB5P You'll need to size the bond wires to the each of your service's. The inspector told me the #6 (I believe that's what the electrician installed when he did the panel upgrade) to the ground rods could have the intersystem bonding bridge clamped to it. He also said to run a #10 from the A/C panel and clamp it to the #6 going to the ground rods. Are those sized correctly? Thanks for the help guys. I'm trying to understand this fully. I know a lot about electricity, but I work with 24VDC military vehicle power systems for a living. Working with digital systems and DC is enough different that I don't know all of the codes for the service entrance side of residential. |
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I recently had my home's electrical service upgraded to 200A and a new Eaton 40 slot panel installed. The electrical inspector came today and the upgrade did not pass inspection for 2 reasons. 1. There is no intersystem bonding bridge for the utility companies to tie into. AT&T currently has a cable clamp on the #4 bare copper wire that runs from the circuit breaker panel to the ground rods outside. The inspector told me I could mount the bridge inside or outside and clamp a #4 wire to the existing wire and run that to the bridge. That's something I can do in an hour, and quite honestly just never noticed it wasn't there. I'll have to look, but I don't think any of the existing cable has enough slack to pull into a bridge if I mount one. 2. My home has interruptible A/C service which is fed by a second meter outside. #6 XHHW-2 runs from this second meter to a separate circuit breaker panel with a 2-pole 30A breaker and a single bus bar with the neutrals connected to it right now. The inspector told me to run a #10 from the panel and connect it to the #4 copper coming from the other panel out to the grounding rods. This is where I'm confused. How should this be grounded? It's not a subpanel because it's fed by the mains, and not by the other panel. Do I need to install a second bus bar for the grounds, or can the ground be connected to the single bus bar in there? I could be showing some ignorance regarding a section of the code that I'm not familiar with.. I think the most appropriate thing to do is take the ground from the 30 amp main disconnect and go directly to the ground rod under a second clamp. That way if either of the two main panels needs to be worked on or swapped out it doesn't interrupt the ground for the other panel. It would probably be worth a follow up call to the inspector to verify his or hers interpretation of the code. 2a. I'm also wondering about my A/C compressor now. There is a fuse box outside next to the compressor with a ground running to the A/C compressor, but that appears to be connected to the same busbar as the neutral?. The 200amp panel looks organized, is that your work? NVM, just read your response above 
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The 200amp panel looks organized, is that your work? Quoted:
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2. My home has interruptible A/C service which is fed by a second meter outside. #6 XHHW-2 runs from this second meter to a separate circuit breaker panel with a 2-pole 30A breaker and a single bus bar with the neutrals connected to it right now. The inspector told me to run a #10 from the panel and connect it to the #4 copper coming from the other panel out to the grounding rods. This is where I'm confused. How should this be grounded? It's not a subpanel because it's fed by the mains, and not by the other panel. Do I need to install a second bus bar for the grounds, or can the ground be connected to the single bus bar in there? I could be showing some ignorance regarding a section of the code that I'm not familiar with.. I think the most appropriate thing to do is take the ground from the 30 amp main disconnect and go directly to the ground rod under a second clamp. That way if either of the two main panels needs to be worked on or swapped out it doesn't interrupt the ground for the other panel. It would probably be worth a follow up call to the inspector to verify his or hers interpretation of the code. The 200amp panel looks organized, is that your work? Regarding your part in blue: A second clamp on the ground rods to allow for independent serviceability is a good idea, and won't be hard to implement. Just so I'm clear, and I've asked this in my reply to previous posters as well, the A/C panel is treated as a main panel, and therefore the bus bar is a combined ground and neutral? That means I can put an appropriately sized ground wire and connect it to the bus in the A/C panel and the ground rods? I don't want to create a secondary current return path, but I believe this isn't an issue since it's not a subpanel to the 200A panel? And no, I did not do the panel work. That was a master electrician who is friends with my roommate. He does primarily commercial work. I would make it look similar to his work though as I have OCD, and I work in a US Army rapid prototype shop producing wiring harnesses for military vehicles among other things. |
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<o:p></o:p> Quoted: Some states allow the use of "SE" cable to run exposed on the outside of the house. It is rated for it (UL) and allowed. (not in my state though) The local AHJ and utility will determine that. This must be the case here. The utility company technician inspected the install prior to upgrading the meter and had no issues. The city electrical inspector has inspected it and also had no issues. Like others have said the A/C has no neutral but, if it is on it own service then there should be a neutral to it (from the service side) and landed on the ground bar with the circuit ground. It wont be used but that's the way it has to be done here (Wa state). So if I understand this, the A/C circuit breaker panel is treated like a main service panel, and not a subpanel. (Correct) Therefore, the single bus bar is a shared ground/neutral bus? (Correct) Therefore, the feed from the meter contains a concentric neutral, but the feed from the panel to the A/C uses the concentric wire as the ground since the A/C compressor does not need a neutral? (Correct) So, to make this correct, I need to connect a ground cable from the bus bar in the A/C panel to the ground cable going to the ground rods? <o:p></o:p> The inter-system bonding is a lug kit like this one http://www.aifittings.com/catalog/grounding/intersystem-grounding-bridges-with-pvc-adapter/GBB5P You'll need to size the bond wires to the each of your service's. The inspector told me the #6 (I believe that's what the electrician installed when he did the panel upgrade) to the ground rods could have the intersystem bonding bridge clamped to it. He also said to run a #10 from the A/C panel and clamp it to the #6 going to the ground rods. Are those sized correctly? I would use #6 for both, no need to buy 2 different wire sizes. Thanks for the help guys. I'm trying to understand this fully. I know a lot about electricity, but I work with 24VDC military vehicle power systems for a living. Working with digital systems and DC is enough different that I don't know all of the codes for the service entrance side of residential. |
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Quoted:
Just so I'm clear, and I've asked this in my reply to previous posters as well, the A/C panel is treated as a main panel, and therefore the bus bar is a combined ground and neutral? That means I can put an appropriately sized ground wire and connect it to the bus in the A/C panel and the ground rods? I don't want to create a secondary current return path, but I believe this isn't an issue since it's not a subpanel to the 200A panel? Beameup answered in the wee hours this morning. Yes, you see the picture correctly, two separate services with two separate main panels. Your electrician just had a brain fart and forgot to run a ground from the 30amp main panel neutral/ground bar to the ground rod. |
OP...You don't have to do anything more then running a piece of #6 bare solid copper or #6 green insulated (any GEC smaller then a #6 copper must be mechanically protected) from the 30A neutral bar to the 200A neutral bar because the 200A busbar meets NEC 250.64 (D)(1)(3) or If in-panel work makes you nervous just split bolt the 30A's GEC to the exposed common (unbroken/continuous) GEC right above your 200A loadcenter. Both practices meet NEC 250.64
Burndy split bolt connector 
For this service upgrade.....I wasn't installing the intersystem bonding bridge near the middle of nowhere NID, so I ran and strapped a new piece of #10 grounding conductor 
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OP...You don't have to do anything more then running a piece of #6 bare solid copper or #6 green insulated (any GEC smaller then a #6 copper must be mechanically protected) from the 30A neutral bar to the 200A neutral bar because the 200A busbar meets NEC 250.64 (D)(1)(3) or If in-panel work makes you nervous just split bolt the 30A's GEC to the exposed common (unbroken/continuous) GEC right above your 200A loadcenter. Both practices meet NEC 250.64 Thanks. I appreciate the NEC references. I have a copy of the 2014 NEC, and like to read the applicable standards when I can, but usually don't know where to look because it's so large and I don't work with it daily like I do MIL-STDs. I'm not afraid of in-panel work, but I'm planning to split bolt it to the existing GEC. That way, if there is ever future work done on the 200A panel, the 30A panel will remain grounded unless someone messes with the GEC outside of the panels. I thought about running the GEC from the 30A panel directly to a second clamp on the ground rods, but the previous owners had a concrete sidewalk poured directly next to the house. The electricians that did the service upgrade used a rotary hammer and bored 2 holes through the sidewalk for the ground rods, connected the GEC with acorn clamps, and sunk them level with the top of the sidewalk. There's no way to get another clamp on there now. I picked up the intersystem bonding bridge, split bolt, and #4 bare copper (matches the existing GEC) today. Forgot the masonry bolts to mount the bridge outside on the brick  Guess I'll do that another day. Didn't really want to do that today anyway with it being 15F outside.
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